Structural - tectonic update of the central Vietnam margin based on analysis of the merged gravity - magnetic and regional seismic data

The central Vietnam margin is part of the western continental margin of the Vietnamese East Sea - the transition zone from the Indochina continental block to the true oceanic crust. In this paper, the authors present new results from merging and interpreting gravity and magnetic data from different sources in combination with 2D seismic and Ocean Drilling Program well data for the central Vietnam margin.The results illustrate the reliability of the merged gravity - magnetic data in regional structural analysis and tectonic division. Five structural layers are vertically identified and characterised by density and thickness. Spatially, six tectonic zones are defined with different Bourguer and magnetic anomaly background values: the boundaries between these zones are clearly delineated by sudden changes of these values. In addition, development signs and extent of the Tuy Hoa Shear Zone on basement rocks are also better resolved compared to the earlier seismic data.